JOHN NORQUIST has learnt how to stop worrying and love congestion. ”It’s like cholesterol,” says the former mayor of Milwaukee, the northern US city made famous by radical politics, beer and the ’70s sitcom Happy Days. ”There’s good congestion and bad congestion.”

Everyone knows about bad congestion. It’s the type you encounter on arterial roads – such as Parramatta Road, Victoria Road and the suburban motorways during peak hour – when you sit, white-knuckled with frustration, in stalled traffic, the car spewing greenhouse gases.

The federal government’s Bureau of Infrastructure, Transport and Regional Economics estimates this congestion will cost Australia $20.4 billion by 2020.

”You don’t want cars sitting there, burning energy,” Norquist says. ”Nor do you want trucks going through the centre of town and not stopping to do business. There’s no economic benefit.”

The census journey to work dataset contains a wealth of data, but analysis of this data is rarely published. This post includes 16 maps showing the concentrations of different modes in the journey to work in Melbourne as recorded in the 2006 Census.